Almost 1,000 whales, dolphins and porpoises die daily in fishing nets and urgent changes are needed in trawling methods to save nine populations under immediate threat, conservation group WWF said on Thursday.
Its report — which WWF says is the first assessment of the situation by leading marine scientists — points to the accidental catching of cetacea in fishing gear as one of the gravest global threats to marine mammals.
“Almost 1,000 whales, dolphins and porpoises die every day in nets and fishing gear. That’s one every two minutes,” said Dr Susan Lieberman, director of WWF’s Global Species Programme.
“Some species are being pushed to the brink of extinction. Urgent action is needed,” she said. Air-breathing mammals, dolphins and other cetacea drown if they get trapped underwater by fishing gear — becoming what the industry refers to as “bycatch”.
The report says nine dolphin and porpoise populations — 10 species in total — need immediate action if they are to survive the threat of commercial fishing nets.
They include harbour porpoises in the Black Sea, the Atlantic humpback dolphins off the coast of West Africa, and Franciscana dolphins in South American waters.
The Irrawaddy dolphins of Southeast Asia, one of the rarest sea mammals on the planet, are also at risk.
“Most of the species on the list are threatened by the widespread use of one type of fishing gear — gillnets,” said WWF.
“These nets are difficult for dolphins and porpoises to spot visually or detect with their sonar, so they may become tangled in the netting or in the ropes attached to the nets,” it said.
But the report says the populations of these threatened creatures could recover with changes to fishing gear combined with other conservation methods.
“Between 1993 and 2003, fisheries in the United States introduced changes, such as modifications of fishing gear, that reduced cetacean bycatch to one-third of its previous levels,” WWF said.
“But so far, few of these successful measures have been transferred to other countries, and in much of the rest of the world, progress to reduce bycatch has been slow or nonexistent.”
Innovations include attaching acoustic alarms to nets which annoy marine mammals — a method that has reduced harbour porpoise deaths in the Gulf of Maine.
WWF said its report would be submitted to the International Whaling Commission’s scientific committee which will be meeting later this month in South Korea.
Ed Stoddard, Reuters